136 Correspondence.


were palpably P. franciscana and the three that lived P. afra, two cocks

and one hen : one of the cock birds I placed in the bird room which is

always fairly warm and the other in a small aviary at the back with a glass

roof, the former came into full colour, but the latter after developing half

way to the breeding plumage just as gradually returned to the winter

plumage (during the whole process forward and backward 110 feathers were

visible on the floor of the little aviary) ; this is the second time that I have

had the same experience of the action of cold upon the colouring of

feathers; but it must be borne in mind that this action only affects feathers

upon living birds.


But the case of the Touracous in which the pigment washed out of a

feather upon the living bird is replaced after a comparatively short time,

so that the feather becomes as brilliant as it was before the bath, will require

a lot of explaining away by those who assert that a perfected feather is life-

less; so also will the teachers of the docttine of perfection in death find it

difficult to explain why the plumage of a dead bird, though not exposed to

the light, should change in tint to such an extent that the pansy blue or

ultramarine on the breast of the living bird is described in a scientific

catalogue as lilac, (and correctly too, as one sees when one examines the

skins from which the description was taken).


I believe, when we get more powerful microscopes with which to

study the internal structures of feathers, it will be found that nutrition is

somehow conveyed even to the most delicate filaments. Seeing is believ-

ing, and at present evidence is not forthcoming, and what can be seen

seems opposed to this belief; but no organism or part of an organism is too

delicate to be supplied with blood-vessels, or numerous insects which barely

surpass in size the motes in a sunbeam could not exist.


A. G. Butter.



THE RED-EYED VIREO.


The folloiving note has been sent to Madame Gorter in reply to a quety :

The Red-eyed Vireo, Greenling or Flycatcher (Vireo olivasceus) is a

bird very seldom imported and not included in the List of Animals which

have lived in the Zoological Gardens. It should be fed like a Song-Thrush,

but with plenty of insect food.


The Vireonidce have been regarded as relations of the Shrikes or

Butcher-birds, but they construct suspended nests after the fashion of the

true Orioles. A. G. BUTTER.



THE GIZA ZOOLOGICAL GARDENS.

Captain Stanley Flower sends us a Report on some valuable additions

which he himself has just brought back to these Gardens from the Sudan.

These consist mostly of mammals, chief amongst which are three African



